On March 11 2011, turbines and reactors of Fukushima Daini Nuclear Power 
Station Units 1 to 4 (Boiling Water Reactors, rated output 1,100 
Megawatts) that we had been constantly operating at rated thermal output 
were automatically shut down at 2:48 pm due to the Tohoku-Chihou-
Taiheiyou-Oki Earthquake occurred at 2:46 pm.
Due to the affect of tsunami accompanied by the earthquake, on each unit 
of 1, 2 and 4 has lost its cooling function of reactor core and as the 
temperature of pressure suppression chamber has exceeded 100°C (which is 
relevant event under the Act on Special Measures Concerning Nuclear 
Emergency Preparedness), Declaration of a Nuclear Emergency Situation was 
issued by the Prime Minister on March 12.
Emergency response measures were taken such as restoration of electric 
motors and recovery of function of residual heat recovery pumps and cold 
shut down has been achieved for each of the unit by March 15. Thereafter, 
emergency response measures had been continuously taken such as 
restoration of power supply functions and diversification of residual heat 
recovery system and we have endeavored to maintain stable cold shut down 
status of the plant.

Implementation status of emergency response measures were confirmed by the 
government that it is in the condition to continuously maintain stable 
cold shut down status of the plant and on December 26, declaration of 
cancellation of a Nuclear Emergency Situation was issued by the Prime 
Minister.

In accordance with the declaration, we will take measures for restoration 
from nuclear emergency to stably maintain cold shut down status of each 
unit and endeavor to enhance stable condition of the plant.

We announce the plant status as of 3:00 pm today per the attachment 
(Updates since the previous press release underlined).

○ The influence of the trouble of switching facilities at 
  Minami-iwaki switching station At approximately 4:10 pm on January 17, due to the trouble of switching
facilities at the Minami-iwaki switching station, the Tomioka line 1 and 2
instantaneously turned to off. The spent fuel pool Coolant purification
system of both Unit 1 and 3 stopped their operation temporarily due to the
event. Later, after confirming that there were no significant problem over
the stopped systems, we started their operation in turn (spent fuel pool
Coolant purification system of Unit 1 at 4:42 pm on the same day; spent
fuel pool Coolant purification system of both Unit 3 at 4:46 pm on the
same day). There is no significant change for the major parameters which
have resulted from the event. 

Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station 
                                                         (PDF 14.0KB)